There are at least three factors to consider in rating the sustainability (http://www.networx.com/article/a-sustainable-design-pyramid) of a flooring product (or many other products). Look for raw materials that are generated in a sustainable and renewable manner. Also consider the chemicals, products and processes involved in manufacturing the raw materials into floorboards. Finally, consider the life expectancy of the product, and the likely future of the product. If a product must be replaced after a few years, and can’t be repurposed, it gets a lower sustainability rating.

For hardwoods, look for products that are approved by the Forest Stewardship Council (FSC) (http://www.networx.com/blog/us-renewing-forests-logo-on-wood-floorin) and the Sustainable Forest Initiative (SFI), which certify sustainably managed forests. Also consider flooring made with little to no volatile organic compounds (VOCs), and minimal processing. Also balance the lifespan of the flooring with the lifespan of the tree. A slow-growth species may last forever, but it also takes forever to replace in the forest.

As to a few of the hardwood replacements, here is the hierarchy of sustainability, from darkest to lightest green.

Reclaimed Wood

Materials: One good alternative to new hardwood flooring is reusing another old hardwood floor. Reclaimed or salvaged hardwood flooring (http://www.networx.com/blog/beetle-kill-lumber-offers-inexpensive-al) literally a recycled product, and one of the only green ways to get old-growth wood, particularly rare or extinct species such as American Chestnut.

Manufacturing: A true reclaimed flooring shouldn’t involve much energy or other inputs other than the transport energy to get the flooring from the old warehouse or barn into your living room. However, watch out for distressed hardwood flooring, which is new hardwood flooring beat up to look. If you go with distressed, follow all the same rules as above for hardwood flooring.

Lifespan: Some reclaimed flooring has lasted well over a century and should last several more lifetimes. If they are ever stripped, they will biodegrade — of they can be reclaimed once again.

Engineered Wood

Materials: Another variation on hardwood planks is engineered wood flooring (http://www.networx.com/article/experts-talk-about-engineered-wood). These typically have up to 10 layers of wood glued together — a hardwood surface over a layer of softwood and a layer of plywood. That’s three types of wood to check for sustainable growth. Look for FSC and SFI certifications, and engineered wood with recycled materials.

Manufacturing: Some engineered woods are manufactured with formaldehyde and other dangerous chemicals in the binders and glues, and may have high VOC levels.

Lifespan: Engineered wood is typically not as durable as hardwood planks, but it holds up better to changes in moisture and humidity. It should last for decades, but it can only be refinished a limited number of times, making it harder to reclaim and giving it a shorter lifespan.

Cork

Materials: Instead of cutting down trees, cork companies strip bark from cork trees to make flooring (as well as bottle stoppers, shoes and much more). The cork is renewed within about a decade. The trees continue growing, and sequestering carbon. Cork plantations are sustainably harvested in the Mediterranean, particularly in Portugal and Spain.

Manufacturing: The cork manufacturing process is also green. Several manufacturers make their cork flooring without any VOCs or solvents. Of course, there is energy involved in getting the cork from Portugal to the U.S.

Lifespan: Life expectancy is the weak spot in cork flooring’s sustainability. Manufacturers promise a lifetime of durability, and there is a Chicago cork church floor dating to 1898 to verify their claims. On the other hand, many users complain about damaging parts of their cork floor with heavy furniture or appliances, and water. This means you will need to replace parts of the floor earlier than you might with true hardwood.